use super::transform::Transform;

use integral_geometry::Size;

use std::rc::Rc;

use vec2d::Vec2D;

#[derive(PartialEq, Clone, Debug)]

pub struct Edge<I: PartialEq + Clone> {

    id: I,

    symmetrical: bool,

    reverse: bool,

}

impl<I: PartialEq + Clone> Edge<I> {

    pub fn new(id: I, symmetrical: bool) -> Self {

        Self {

            id,

            symmetrical,

            reverse: false,

        }

    }

    pub fn reversed(&self) -> Self {

        Self {

            id: self.id.clone(),

            symmetrical: self.symmetrical,

            reverse: !self.symmetrical && !self.reverse,

        }

    }

    pub fn is_compatible(&self, other: &Self) -> bool {

        self.id == other.id && ((self.reverse != other.reverse) || self.symmetrical)

    }

}

#[derive(Clone)]

pub struct TileImage<T, I: PartialEq + Clone> {

    image: Rc<Vec2D<T>>,

    pub transform: Transform,

    top: Edge<I>,

    right: Edge<I>,

    bottom: Edge<I>,

    left: Edge<I>,

}

impl<T: Copy, I: PartialEq + Clone> TileImage<T, I> {

    pub fn new(

        image: Vec2D<T>,

        top: Edge<I>,

        right: Edge<I>,

        bottom: Edge<I>,

        left: Edge<I>,

    ) -> Self {

        Self {

            image: Rc::new(image),

            transform: Transform::default(),

            top,

            right,

            bottom,

            left,

        }

    }

    pub fn mirrored(&self) -> Self {

        Self {

            image: self.image.clone(),

            transform: self.transform.mirror(),

            top: self.top.reversed(),

            right: self.left.reversed(),

            bottom: self.bottom.reversed(),

            left: self.right.reversed(),

        }

    }

    pub fn flipped(&self) -> Self {

        Self {

            image: self.image.clone(),

            transform: self.transform.flip(),

            top: self.bottom.reversed(),

            right: self.right.reversed(),

            bottom: self.top.reversed(),

            left: self.left.reversed(),

        }

    }

    pub fn rotated90(&self) -> Self {

        Self {

            image: self.image.clone(),

            transform: self.transform.rotate90(),

            top: self.left.clone(),

            right: self.top.clone(),

            bottom: self.right.clone(),

            left: self.bottom.clone(),

        }

    }

    pub fn rotated180(&self) -> Self {

        Self {

            image: self.image.clone(),

            transform: self.transform.rotate180(),

            top: self.bottom.clone(),

            right: self.left.clone(),

            bottom: self.top.clone(),

            left: self.right.clone(),

        }

    }

    pub fn rotated270(&self) -> Self {

        Self {

            image: self.image.clone(),

            transform: self.transform.rotate270(),

            top: self.right.clone(),

            right: self.bottom.clone(),

            bottom: self.left.clone(),

            left: self.top.clone(),

        }

    }

    pub fn right_edge(&self) -> &Edge<I> {

        &self.right

    }

    pub fn bottom_edge(&self) -> &Edge<I> {

        &self.bottom

    }

    pub fn left_edge(&self) -> &Edge<I> {

        &self.left

    }

    pub fn top_edge(&self) -> &Edge<I> {

        &self.top

    }

    pub fn size(&self) -> Size {

        match self.transform {

            Transform::Rotate0(_) => self.image.size(),

            Transform::Rotate90(_) => Size::new(self.image.size().height, self.image.size().width),

        }

    }

    pub fn get(&self, row: usize, column: usize) -> Option<&T> {

        match self.transform {

            Transform::Rotate0(_) => {

                let image_row = if self.transform.is_flipped() {

                    self.image.height().wrapping_sub(1).wrapping_sub(row)

                } else {

                    row

                };

                let image_column = if self.transform.is_mirrored() {

                    self.image.width().wrapping_sub(1).wrapping_sub(column)

                } else {

                    column

                };

                self.image.get(image_row, image_column)

            }

            Transform::Rotate90(_) => {

                let image_row = if self.transform.is_mirrored() {

                    column

                } else {

                    self.image.height().wrapping_sub(1).wrapping_sub(column)

                };

                let image_column = if self.transform.is_flipped() {

                    self.image.width().wrapping_sub(1).wrapping_sub(row)

                } else {

                    row

                };

                self.image.get(image_row, image_column)

            }

        }

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    #[test]

    fn test_edge_new() {

        let edge = Edge::new(1, true);

        assert_eq!(edge.id, 1);

        assert_eq!(edge.symmetrical, true);

        assert_eq!(edge.reverse, false);

    }

    #[test]

    fn test_edge_reversed() {

        let edge = Edge::new(1, true);

        let reversed = edge.reversed();

        assert_eq!(reversed.id, edge.id);

        assert_eq!(reversed.symmetrical, edge.symmetrical);

        assert_eq!(reversed.reverse, false);

        let edge = Edge::new(1, false);

        let reversed = edge.reversed();

        assert_eq!(reversed.id, edge.id);

        assert_eq!(reversed.symmetrical, edge.symmetrical);

        assert_eq!(reversed.reverse, true);

    }

    #[test]

    fn test_edge_equality() {

        let edge1 = Edge::new(1, true);

        let edge2 = Edge::new(1, true);

        assert_eq!(edge1, edge2);

        let edge1 = Edge::new(1, false);

        let edge2 = Edge::new(1, false);

        assert_eq!(edge1, edge2);

        let edge1 = Edge::new(1, false);

        let edge2 = Edge::new(2, false);

        assert_ne!(edge1, edge2);

    }

    #[test]

    fn test_edge_equality_with_reverse() {

        let edge1 = Edge::new(1, true);

        let edge2 = edge1.reversed();

        assert_eq!(edge1, edge2);

        let edge1 = Edge::new(1, false);

        let edge2 = edge1.reversed();

        assert_ne!(edge1, edge2);

        let edge1 = Edge::new(1, true);

        let edge2 = edge1.reversed().reversed();

        assert_eq!(edge1, edge2);

    }

}